California projected to get wetter through this century

California projected to get wetter through this century
Scientists at the University of California, Riverside predict California will get an average of 12 percent more precipitation through the end of this century, compared to the last 20 years of last century. Credit: UC Riverside Strategic Communications.

Under business-as-usual greenhouse gas emissions, climate models predict California will get warmer during the rest of the century and most also predict the state will get drier.

But, new research, published today in the journal Nature Communications, predicts that California will actually get wetter. The scientists from the University of California, Riverside predict the state will get an average of 12 percent more through the end of this century, compared to the last 20 years of last century.

The researchers found different rates of precipitation increase for northern, central and southern California. Northern California, which they define as starting just north of Santa Rosa, would increase 14.1 percent. Central California, which starts just south of San Luis Opispo, would go up 15.2 percent. Southern California would actually decrease 3.3 percent.

They also found the winter months of December, January and February, when California traditionally gets the bulk of its precipitation, would account for much of the overall increase in precipitation. During those three months, precipitation levels would increase 31.6 percent in northern California, 39.2 percent in central California and 10.6 percent in southern California.

All these percentages are in comparison to data from the Global Precipitation Climatology Project observed between 1979 and 1999.

"Most previous research emphasized uncertainty with regards to future precipitation levels in California, but the overall thought was California would become drier with continued climate change," said Robert Allen, an associate professor at UC Riverside and one of the authors of the paper. "We found the opposite, which is quite surprising."

The past uncertainty as to whether California would get more precipitation in the future was due to several factors, including year-to-year variations in individual weather events, shortcomings in models and because California lies within a transition zone, where northern parts of the state are expected to become wetter and southern portions are expected to be drier.

Allen, a faculty member in the Department of Earth Sciences, and Rainer Luptowitz, a graduate student working with Allen, analyzed 38 developed around the world to reach their conclusions.

They found that warming in the tropical eastern Pacific Ocean , an area about 2,500 miles east of the international date line, is the main reason for the predicted increase in precipitation levels.

The warming sea surface temperatures encourage a southeastward shift of the jet stream, which helps steer more rain-producing mid-latitude cyclones toward California.

"Essentially, this mechanism is similar to what we in California expect during an El Nino year," Allen said. "Ultimately, what I am arguing is El Nino-like years are going to become more the norm in California."

But, Allen cautions that prediction of an El Nino-like year is no guarantee of a more wet winter in California. The 2015-16 winter was an example of that. Many other climatic factors must be considered.


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Journal information: Nature Communications

Citation: California projected to get wetter through this century (2017, July 6) retrieved 16 July 2019 from https://phys.org/news/2017-07-california-wetter-century.html
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Jul 06, 2017
So, to sum up, it could be wetter, or possibly drier, or maybe even remain the same

Jul 06, 2017
No matter what happens it's because of man made CO2 ..
Just 15% Of CO2 Growth Since Industrialization Is Due To Human Emissions.
Water vapour is 90% of the greenhouse effect, why would you even look at CO2?

Jul 06, 2017
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Jul 06, 2017
On average, if the temperature goes up, there will be more evaporation. If more evaporation, then there will be more precipitation. Just stating the obvious.


Jul 06, 2017
So many of you just refuse to understand, when climate changes, it gets wetter in some places, drier in others; also hotter in some and colder in others. Modeling the entire planet's weather is hard work, and all they could say before is that things would change in disruptive ways. But they have been refining the models, and now they are starting to be able to give more precise predictions.

Wetter winters do not necessarily mean things will be fine, or better for agriculture, even. Winters should also be warmer, which means less snow and more rain. That means more flooding in winter and spring, and possibly drier summers. The inland areas could even end up drier, not wetter, depending on where and when and how the precipitation falls.

Also, if the land has been clear cut (96% of all redwoods have already been cut down), then the land will have reduced capacity to capture water. Erosion will be worse.

Stop knee-jerking and think about facts and consequences.

Jul 06, 2017
Here's from another article today about the Sahel getting wetter under global warming:
These storms supply about 90 percent of the region's rainfall—but more tempests do not equate to more water. Water from violent storms tends to run off and not filter into the soil where crops can benefit.

It also washes away nutrient-holding agricultural soil in a region still recovering from a historic 20-year drought between the 1970s and 1990s.

Read more at: https://phys.org/...html#jCp

So, wetter could be catastrophic, not wonderful.

Jul 06, 2017
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Jul 06, 2017
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Jul 06, 2017
Is this the same California that they declared to be in permadrought?

Jul 06, 2017
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Jul 07, 2017
"Business as usual? What does CO2 have to do with it?

Jul 07, 2017
If only there was a form of government were the elites ran things and were immune to the passions and immaturity of the prols.

Jul 07, 2017
If only there was a form of government were the elites ran things and were immune to the passions and immaturity of the prols.


I'd say that that would be a Good Thing.

If the ignorant "passions and immaturity of the prols" leads our specie's actions to the exclusion of Science, which they clearly are incapable of understanding, then we're all doomed. The "Wisdom of the Mob" isn't exactly a catch-phrase.

But, in true Soylent Green fashion, they'll at least make a good food source in the final days.

Jul 08, 2017
I'm impressed by the level of anti-science activity in this thread. It brings to mind creationists who believe that every new species discovered is a refutation of evolution as a whole, since now there's a new "missing link" between that species and another.

More refinement of a model does not constitute a failure of the concepts that the model is built on.

Jul 08, 2017
"They also found the winter months of December, January and February, when California traditionally gets the bulk of its precipitation, would account for much of the overall increase in precipitation.

"

Great, more mudslides. ;P

Jul 09, 2017
The Paris Accord decreases the predicted global warming by 1% over 100 years for a trillion dollars. Seems like a joke.

Jul 09, 2017
The increase in atmospheric CO2 is the result of a warming climate, not the cause of it. ALL of this nonsense is just a transfer of wealth scam!

Jul 10, 2017
@gmeyers: Who's paying hundreds of thousands of climatologists, volcanologists, oceanographers, physicists, astrophysicists, meteorologists, biologists, geologists, and countless other experts to keep up your conspiracy? Remember, any one of them stands to make millions of dollars by breaking it and revealing it to the press, so the bribes are at least as much.

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